/*! ----------------------------------------------------------------------------
 *  @file    main.c
 *  @brief   Double-sided two-way ranging (DS TWR) initiator example code
 *
 *           This is a simple code example which acts as the initiator in a DS TWR distance measurement exchange. This application sends a "poll"
 *           frame (recording the TX time-stamp of the poll), and then waits for a "response" message expected from the "DS TWR responder" example
 *           code (companion to this application). When the response is received its RX time-stamp is recorded and we send a "final" message to
 *           complete the exchange. The final message contains all the time-stamps recorded by this application, including the calculated/predicted TX
 *           time-stamp for the final message itself. The companion "DS TWR responder" example application works out the time-of-flight over-the-air
 *           and, thus, the estimated distance between the two devices.
 *
 * @attention
 *
 * Copyright 2015 (c) Decawave Ltd, Dublin, Ireland.
 *
 * All rights reserved.
 *
 * @author Decawave
 */

#include <string.h>
#include "dw_app.h"
#include "deca_device_api.h"
#include "deca_regs.h"
#include "dw_driver.h"
#include "Spi.h"
#include "led.h"
#include "serial_at_cmd_app.h"
#include "Usart.h"
#include "global_param.h"
#include "filters.h"
#include <stdio.h>
#include "beep.h"


/*------------------------------------ Marcos ------------------------------------------*/
/* Inter-ranging delay period, in milliseconds. */
#define RNG_DELAY_MS 100

/* Default antenna delay values for 64 MHz PRF. See NOTE 1 below. */
#define TX_ANT_DLY 0
#define RX_ANT_DLY 32899

/* UWB microsecond (uus) to device time unit (dtu, around 15.65 ps) conversion factor.
 * 1 uus = 512 / 499.2 µs and 1 µs = 499.2 * 128 dtu. */
#define UUS_TO_DWT_TIME 65536

/* Delay between frames, in UWB microseconds. See NOTE 4 below. */
/* This is the delay from the end of the frame transmission to the enable of the receiver, as programmed for the DW1000's wait for response feature. */
#define POLL_TX_TO_RESP_RX_DLY_UUS 150
/* This is the delay from Frame RX timestamp to TX reply timestamp used for calculating/setting the DW1000's delayed TX function. This includes the
 * frame length of approximately 2.66 ms with above configuration. */
#define RESP_RX_TO_FINAL_TX_DLY_UUS 1500
/* Receive response timeout. See NOTE 5 below. */
#define RESP_RX_TIMEOUT_UUS 2700

#define POLL_RX_TO_RESP_TX_DLY_UUS 420
/* This is the delay from the end of the frame transmission to the enable of the receiver, as programmed for the DW1000's wait for response feature. */
#define RESP_TX_TO_FINAL_RX_DLY_UUS 200
/* Receive final timeout. See NOTE 5 below. */
#define FINAL_RX_TIMEOUT_UUS 4300

#define SPEED_OF_LIGHT 299702547

/* Indexes to access some of the fields in the frames defined above. */
#define ALL_MSG_SN_IDX 2
#define FINAL_MSG_POLL_TX_TS_IDX 10
#define FINAL_MSG_RESP_RX_TS_IDX 14
#define FINAL_MSG_FINAL_TX_TS_IDX 18
#define FINAL_MSG_TS_LEN 4

#define GROUP_ID_IDX   				0
#define ANCHOR_ID_IDX    			1
#define TAG_ID_IDX    				3
#define MESSAGE_TYPE_IDX 			5
#define DIST_IDX 							6

#define POLL     					0x01
#define RESPONSE 					0x02
#define FINAL   					0x03

/*------------------------------------ Variables ------------------------------------------*/
/* Default communication configuration. We use here EVK1000's default mode (mode 3). */
static dwt_config_t config = {
	2,               /* Channel number. */
	DWT_PRF_64M,     /* Pulse repetition frequency. */
	DWT_PLEN_128,    /* Preamble length. */
	DWT_PAC8,        /* Preamble acquisition chunk size. Used in RX only. */
	9,               /* TX preamble code. Used in TX only. */
	9,               /* RX preamble code. Used in RX only. */
	0,               /* Use non-standard SFD (Boolean) */
	DWT_BR_6M8,      /* Data rate. */
	DWT_PHRMODE_STD, /* PHY header mode. */
	(129 + 8 - 8)    /* SFD timeout (preamble length + 1 + SFD length - PAC size). Used in RX only. */
};

/* Frames used in the ranging process. See NOTE 2 below. */
static uint8_t tx_poll_msg[] = {0x00, 0x88, 0, 0xCA, 0xDE, 'W', 'A', 'V', 'E', 0x21, 0, 0};
//static uint8_t rx_resp_msg[] = {0x41, 0x88, 0, 0xCA, 0xDE, 'V', 'E', 'W', 'A', 0x10, 0x02, 0, 0, 0, 0};
static uint8_t tx_final_msg[] = {0x41, 0x88, 0, 0xCA, 0xDE, 'W', 'A', 'V', 'E', 0x23, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
	
//static uint8_t rx_poll_msg[] = {0x00, 0x88, 0, 0xCA, 0xDE, 'W', 'A', 'V', 'E', 0x21, 0, 0};
static uint8_t tx_resp_msg[] = {0x41, 0x88, 0, 0xCA, 0xDE, 'V', 'E', 'W', 'A', 0x10, 0x02, 0, 0, 0, 0};
//static uint8_t rx_final_msg[] = {0x41, 0x88, 0, 0xCA, 0xDE, 'W', 'A', 'V', 'E', 0x23, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
	
/* Frame sequence number, incremented after each transmission. */
static uint32_t frame_seq_nb = 0;	
	
/* Hold copy of status register state here for reference, so reader can examine it at a breakpoint. */
static uint32_t status_reg = 0;
	
/* Buffer to store received response message.
 * Its size is adjusted to longest frame that this example code is supposed to handle. */
#define RX_BUF_LEN 		24
static uint8_t rx_buffer[RX_BUF_LEN];
	
/* Time-stamps of frames transmission/reception, expressed in device time units.
 * As they are 40-bit wide, we need to define a 64-bit int type to handle them. */
static uint64_t poll_tx_ts;
static uint64_t resp_rx_ts;
static uint64_t final_tx_ts;
	
/* Length of the common part of the message (up to and including the function code, see NOTE 2 below). */
static uint64_t poll_rx_ts;
static uint64_t resp_tx_ts;
static uint64_t final_rx_ts;

static double tof;
	
uint16_t anchor_dist_last_frm[TAG_NUM_IN_SYS];	
uint8_t tag_id = 0;
uint8_t tag_id_recv = 0;
uint8_t random_delay_tim = 0;

double distance, dist_no_bias, dist_cm;

uint32_t g_UWB_com_interval = 0; 
float dis_after_filter;				//µ±Ç°¾àÀëÖµ
LPFilter_Frac* p_Dis_Filter;		//²â¾àÓõĵÍͨÂ˲¨Æ÷

uint16_t g_Tagdist[256];
uint8_t g_flag_Taggetdist[256];
/*------------------------------------ Functions ------------------------------------------*/


/*! ------------------------------------------------------------------------------------------------------------------
 * @fn get_tx_timestamp_u64()
 *
 * @brief Get the TX time-stamp in a 64-bit variable.
 *        /!\ This function assumes that length of time-stamps is 40 bits, for both TX and RX!
 *
 * @param  none
 *
 * @return  64-bit value of the read time-stamp.
 */
static uint64_t get_tx_timestamp_u64(void)
{
    uint8_t ts_tab[5];
    uint64_t ts = 0;
    int i;
    dwt_readtxtimestamp(ts_tab);
    for (i = 4; i >= 0; i--)
    {
        ts <<= 8;
        ts |= ts_tab[i];
    }
    return ts;
}

/*! ------------------------------------------------------------------------------------------------------------------
 * @fn get_rx_timestamp_u64()
 *
 * @brief Get the RX time-stamp in a 64-bit variable.
 *        /!\ This function assumes that length of time-stamps is 40 bits, for both TX and RX!
 *
 * @param  none
 *
 * @return  64-bit value of the read time-stamp.
 */
static uint64_t get_rx_timestamp_u64(void)
{
    uint8_t ts_tab[5];
    uint64_t ts = 0;
    int i;
    dwt_readrxtimestamp(ts_tab);
    for (i = 4; i >= 0; i--)
    {
        ts <<= 8;
        ts |= ts_tab[i];
    }
    return ts;
}

/*! ------------------------------------------------------------------------------------------------------------------
 * @fn final_msg_set_ts()
 *
 * @brief Fill a given timestamp field in the final message with the given value. In the timestamp fields of the final
 *        message, the least significant byte is at the lower address.
 *
 * @param  ts_field  pointer on the first byte of the timestamp field to fill
 *         ts  timestamp value
 *
 * @return none
 */
static void final_msg_set_ts(uint8_t *ts_field, uint64_t ts)
{
    int i;
    for (i = 0; i < FINAL_MSG_TS_LEN; i++)
    {
        ts_field[i] = (uint8_t) ts;
        ts >>= 8;
    }
}

static void final_msg_get_ts(const uint8_t *ts_field, uint32_t *ts)
{
    int i;
    *ts = 0;
    for (i = 0; i < FINAL_MSG_TS_LEN; i++)
    {
        *ts += ts_field[i] << (i * 8);
    }
}
void TagDistClear(void)
{
	static uint16_t clear_judge_cnt;
	uint16_t i;
	if(clear_judge_cnt++>1000)  //É趨1S·ÖƵ£¬Ã¿Ãë½øÒ»´Î¡£Åжϱê־λ´óÓÚµÈÓÚ2£¬2sûÊÕµ½Êý¾Ý¾Í°ÑÊý¾Ý±ä³É0xffff£¬²»´¥·¢¾¯±¨¡£
	{
		clear_judge_cnt=0;
		for(i=0;i<255;i++)
		{
			g_flag_Taggetdist[i]++;
			if(g_flag_Taggetdist[i]>=2)
			{
				g_Tagdist[i]=0xffff;
			}
		}
	}
}
void Dw1000_Init(void)
{
	/* Reset and initialise DW1000.
     * For initialisation, DW1000 clocks must be temporarily set to crystal speed. After initialisation SPI rate can be increased for optimum
     * performance. */
    Reset_DW1000();//ÖØÆôDW1000 /* Target specific drive of RSTn line into DW1000 low for a period. */
    dwt_initialise(DWT_LOADUCODE);//³õʼ»¯DW1000
	Spi_ChangePrescaler(SPIx_PRESCALER_FAST);	//ÉèÖÃΪ¿ìËÙģʽ

    /* Configure DW1000. See NOTE 6 below. */
    dwt_configure(&config);//ÅäÖÃDW1000
	

	
    /* Apply default antenna delay value. See NOTE 1 below. */
    dwt_setrxantennadelay(RX_ANT_DLY);		//ÉèÖýÓÊÕÌìÏßÑÓ³Ù
    dwt_settxantennadelay(TX_ANT_DLY);		//ÉèÖ÷¢ÉäÌìÏßÑÓ³Ù

    /* Set expected response's delay and timeout. See NOTE 4 and 5 below.
     * As this example only handles one incoming frame with always the same delay and timeout, those values can be set here once for all. */
    dwt_setrxaftertxdelay(POLL_TX_TO_RESP_RX_DLY_UUS);			//ÉèÖ÷¢Ëͺó¿ªÆô½ÓÊÕ£¬²¢É趨ÑÓ³Ùʱ¼ä
    dwt_setrxtimeout(RESP_RX_TIMEOUT_UUS);						//ÉèÖýÓÊÕ³¬Ê±Ê±¼ä
}
void Dw1000_App_Init(void)
{
//	g_com_map[DEV_ID] = 0x02;
	tx_poll_msg[MESSAGE_TYPE_IDX]=POLL;
	tx_resp_msg[MESSAGE_TYPE_IDX]=RESPONSE;
	tx_final_msg[MESSAGE_TYPE_IDX]=FINAL;
	memcpy(&tx_poll_msg[TAG_ID_IDX], &g_com_map[DEV_ID], 2);
	memcpy(&tx_final_msg[TAG_ID_IDX], &g_com_map[DEV_ID], 2);
	memcpy(&tx_resp_msg[ANCHOR_ID_IDX], &g_com_map[DEV_ID], 2);
	
}	
void tag_sleep_configuraion(void)
{
	dwt_configuresleep(0x940, 0x7);
	dwt_entersleep();
}
uint16_t g_Resttimer;
uint8_t result;
void Tag_App(void)//·¢ËÍģʽ(TAG±êÇ©)
{
	uint32_t frame_len;
	uint32_t final_tx_time;
	
	g_Resttimer=0;
	UART_CheckReceive();
	GPIO_ResetBits(SPIx_GPIO, SPIx_CS);
	delay_us(2500);
	GPIO_SetBits(SPIx_GPIO, SPIx_CS);
	
	/* Write frame data to DW1000 and prepare transmission. See NOTE 7 below. */
	tx_poll_msg[ALL_MSG_SN_IDX] = frame_seq_nb;
	dwt_writetxdata(sizeof(tx_poll_msg), tx_poll_msg, 0);//½«Poll°üÊý¾Ý´«¸øDW1000£¬½«ÔÚ¿ªÆô·¢ËÍʱ´«³öÈ¥
	dwt_writetxfctrl(sizeof(tx_poll_msg), 0);//ÉèÖó¬¿í´ø·¢ËÍÊý¾Ý³¤¶È

	/* Start transmission, indicating that a response is expected so that reception is enabled automatically after the frame is sent and the delay
	 * set by dwt_setrxaftertxdelay() has elapsed. */
	dwt_starttx(DWT_START_TX_IMMEDIATE | DWT_RESPONSE_EXPECTED);//¿ªÆô·¢ËÍ£¬·¢ËÍÍê³ÉºóµÈ´ýÒ»¶Îʱ¼ä¿ªÆô½ÓÊÕ£¬µÈ´ýʱ¼äÔÚdwt_setrxaftertxdelayÖÐÉèÖÃ

	/* We assume that the transmission is achieved correctly, poll for reception of a frame or error/timeout. See NOTE 8 below. */
	while (!((status_reg = dwt_read32bitreg(SYS_STATUS_ID)) & (SYS_STATUS_RXFCG | SYS_STATUS_ALL_RX_ERR)))//²»¶Ï²éѯоƬ״ֱ̬µ½³É¹¦½ÓÊÕ»òÕß·¢Éú´íÎó
	{ };

	/* Increment frame sequence number after transmission of the poll message (modulo 256). */
	frame_seq_nb++;

	if (status_reg & SYS_STATUS_RXFCG)//Èç¹û³É¹¦½ÓÊÕ
	{
		/* Clear good RX frame event and TX frame sent in the DW1000 status register. */
		dwt_write32bitreg(SYS_STATUS_ID, SYS_STATUS_RXFCG | SYS_STATUS_TXFRS);//Çå³þ¼Ä´æÆ÷±ê־λ

		/* A frame has been received, read it into the local buffer. */
		frame_len = dwt_read32bitreg(RX_FINFO_ID) & RX_FINFO_RXFLEN_MASK;	//»ñµÃ½ÓÊÕµ½µÄÊý¾Ý³¤¶È

		dwt_readrxdata(rx_buffer, frame_len, 0);   //¶ÁÈ¡½ÓÊÕÊý¾Ý


		/* Check that the frame is the expected response from the companion "DS TWR responder" example.
		 * As the sequence number field of the frame is not relevant, it is cleared to simplify the validation of the frame. */
		rx_buffer[ALL_MSG_SN_IDX] = 0;
		if (rx_buffer[MESSAGE_TYPE_IDX] == RESPONSE) //ÅжϽÓÊÕµ½µÄÊý¾ÝÊÇ·ñÊÇresponseÊý¾Ý
		{
			/* Retrieve poll transmission and response reception timestamp. */
			poll_tx_ts = get_tx_timestamp_u64();										//»ñµÃPOLL·¢ËÍʱ¼äT1
			resp_rx_ts = get_rx_timestamp_u64();										//»ñµÃRESPONSE½ÓÊÕʱ¼äT4
			
			memcpy(&anchor_dist_last_frm[tag_id], &rx_buffer[DIST_IDX], 2);
			memcpy(&tx_final_msg[ANCHOR_ID_IDX], &rx_buffer[ANCHOR_ID_IDX], 2);
			/* Compute final message transmission time. See NOTE 9 below. */
			final_tx_time = (resp_rx_ts + (RESP_RX_TO_FINAL_TX_DLY_UUS * UUS_TO_DWT_TIME)) >> 8;//¼ÆËãfinal°ü·¢ËÍʱ¼ä£¬T5=T4+Treply2
			dwt_setdelayedtrxtime(final_tx_time);//ÉèÖÃfinal°ü·¢ËÍʱ¼äT5

			/* Final TX timestamp is the transmission time we programmed plus the TX antenna delay. */
			final_tx_ts = (((uint64_t)(final_tx_time & 0xFFFFFFFE)) << 8) + TX_ANT_DLY;//final°üʵ¼Ê·¢ËÍʱ¼äÊǼÆËãʱ¼ä¼ÓÉÏ·¢ËÍÌìÏßdelay

			/* Write all timestamps in the final message. See NOTE 10 below. */
			final_msg_set_ts(&tx_final_msg[FINAL_MSG_POLL_TX_TS_IDX], poll_tx_ts);//½«T1£¬T4£¬T5дÈë·¢ËÍÊý¾Ý
			final_msg_set_ts(&tx_final_msg[FINAL_MSG_RESP_RX_TS_IDX], resp_rx_ts);
			final_msg_set_ts(&tx_final_msg[FINAL_MSG_FINAL_TX_TS_IDX], final_tx_ts);

			/* Write and send final message. See NOTE 7 below. */
			tx_final_msg[ALL_MSG_SN_IDX] = frame_seq_nb;
			dwt_writetxdata(sizeof(tx_final_msg), tx_final_msg, 0);//½«·¢ËÍÊý¾ÝдÈëDW1000
			dwt_writetxfctrl(sizeof(tx_final_msg), 0);//É趨·¢ËÍÊý¾Ý³¤¶È
			result=dwt_starttx(DWT_START_TX_DELAYED);//É趨ΪÑÓ³Ù·¢ËÍ
			
			
			/* Poll DW1000 until TX frame sent event set. See NOTE 8 below. */
			if(result==0)
			{while (!(dwt_read32bitreg(SYS_STATUS_ID) & SYS_STATUS_TXFRS))//²»¶Ï²éѯоƬ״ֱ̬µ½·¢ËÍÍê³É
			{ };
		}
			/* Clear TXFRS event. */
			dwt_write32bitreg(SYS_STATUS_ID, SYS_STATUS_TXFRS);//Çå³ý±ê־λ

			/* Increment frame sequence number after transmission of the final message (modulo 256). */
			frame_seq_nb++;
			random_delay_tim = 0;
		}
		else
		{
			random_delay_tim = DFT_RAND_DLY_TIM_MS; //Èç¹ûͨѶʧ°Ü£¬½«¼ä¸ôʱ¼äÔö¼Ó5ms£¬±Ü¿ªÒòΪ¶à±êǩͬʱ·¢ËÍÒýÆðµÄ³åÍ»¡£
		}
	}
	else
	{
		/* Clear RX error events in the DW1000 status register. */
		dwt_write32bitreg(SYS_STATUS_ID, SYS_STATUS_ALL_RX_ERR);
		random_delay_tim = DFT_RAND_DLY_TIM_MS;
	}
	LED0_BLINK;
	/* Execute a delay between ranging exchanges. */
	dwt_entersleep();
	
}
extern uint8_t g_pairstart;
void Anchor_App(void)
{
	uint32_t frame_len;
	uint32_t resp_tx_time;
	
	/* Clear reception timeout to start next ranging process. */
	dwt_setrxtimeout(0);//É趨½ÓÊÕ³¬Ê±Ê±¼ä£¬0λûÓг¬Ê±Ê±¼ä

	/* Activate reception immediately. */
	dwt_rxenable(0);//´ò¿ª½ÓÊÕ

	/* Poll for reception of a frame or error/timeout. See NOTE 7 below. */
	while (!((status_reg = dwt_read32bitreg(SYS_STATUS_ID)) & (SYS_STATUS_RXFCG | SYS_STATUS_ALL_RX_ERR)))//²»¶Ï²éѯоƬ״ֱ̬µ½½ÓÊճɹ¦»òÕß³öÏÖ´íÎó
	{ 
		UART_CheckReceive();
		g_Resttimer=0;
	};

	if (status_reg & SYS_STATUS_RXFCG)//³É¹¦½ÓÊÕ
	{
		/* Clear good RX frame event in the DW1000 status register. */
		dwt_write32bitreg(SYS_STATUS_ID, SYS_STATUS_RXFCG);//Çå³ý±ê־λ

		/* A frame has been received, read it into the local buffer. */
		frame_len = dwt_read32bitreg(RX_FINFO_ID) & RX_FINFO_RXFL_MASK_1023;//»ñµÃ½ÓÊÕÊý¾Ý³¤¶È

		dwt_readrxdata(rx_buffer, frame_len, 0);//¶ÁÈ¡½ÓÊÕÊý¾Ý


		/* Check that the frame is a poll sent by "DS TWR initiator" example.
		 * As the sequence number field of the frame is not relevant, it is cleared to simplify the validation of the frame. */
		rx_buffer[ALL_MSG_SN_IDX] = 0;
		
		//½«ÊÕµ½µÄtag_id·Ö±ðдÈë¸÷´ÎͨѶµÄ°üÖУ¬Îª¶à±êǩͨѶ·þÎñ£¬·ÀÖ¹Ò»´ÎͨѶÖнÓÊÕµ½²»Í¬ID±êÇ©µÄÊý¾Ý
		tag_id_recv = rx_buffer[TAG_ID_IDX];
		tx_resp_msg[TAG_ID_IDX] = tag_id_recv;

		
		if (rx_buffer[MESSAGE_TYPE_IDX] == POLL&&tag_id_recv!= g_com_map[PAIR_ID]) //ÅжÏÊÇ·ñÊÇpoll°üÊý¾Ý
		{
			/* Retrieve poll reception timestamp. */
			poll_rx_ts = get_rx_timestamp_u64();//»ñµÃPoll°ü½ÓÊÕʱ¼äT2

			/* Set send time for response. See NOTE 8 below. */
			resp_tx_time = (poll_rx_ts + (POLL_RX_TO_RESP_TX_DLY_UUS * UUS_TO_DWT_TIME)) >> 8;//¼ÆËãResponse·¢ËÍʱ¼äT3¡£
			dwt_setdelayedtrxtime(resp_tx_time);//ÉèÖÃResponse·¢ËÍʱ¼äT3

			/* Set expected delay and timeout for final message reception. */
			dwt_setrxaftertxdelay(RESP_TX_TO_FINAL_RX_DLY_UUS);//ÉèÖ÷¢ËÍÍê³Éºó¿ªÆô½ÓÊÕÑÓ³Ùʱ¼ä
			dwt_setrxtimeout(FINAL_RX_TIMEOUT_UUS);//½ÓÊÕ³¬Ê±Ê±¼ä

			/* Write and send the response message. See NOTE 9 below.*/
			memcpy(&tx_resp_msg[DIST_IDX], &anchor_dist_last_frm[tag_id_recv], 2);
			tx_resp_msg[ALL_MSG_SN_IDX] = frame_seq_nb;
			dwt_writetxdata(sizeof(tx_resp_msg), tx_resp_msg, 0);//дÈë·¢ËÍÊý¾Ý
			dwt_writetxfctrl(sizeof(tx_resp_msg), 0);//É趨·¢Ëͳ¤¶È
			result = dwt_starttx(DWT_START_TX_DELAYED | DWT_RESPONSE_EXPECTED);//ÑÓ³Ù·¢ËÍ£¬µÈ´ý½ÓÊÕ

			/* We assume that the transmission is achieved correctly, now poll for reception of expected "final" frame or error/timeout.
			 * See NOTE 7 below. */
			if(result==0)
			{
				while (!((status_reg = dwt_read32bitreg(SYS_STATUS_ID)) & (SYS_STATUS_RXFCG | SYS_STATUS_ALL_RX_ERR)))///²»¶Ï²éѯоƬ״ֱ̬µ½½ÓÊճɹ¦»òÕß³öÏÖ´íÎó
			{ };
		}
			/* Increment frame sequence number after transmission of the response message (modulo 256). */
			frame_seq_nb++;

			if (status_reg & SYS_STATUS_RXFCG)//½ÓÊճɹ¦
			{
				/* Clear good RX frame event and TX frame sent in the DW1000 status register. */
				dwt_write32bitreg(SYS_STATUS_ID, SYS_STATUS_RXFCG | SYS_STATUS_TXFRS);//Çå³þ±ê־λ

				/* A frame has been received, read it into the local buffer. */
				frame_len = dwt_read32bitreg(RX_FINFO_ID) & RX_FINFO_RXFLEN_MASK;//Êý¾Ý³¤¶È

				dwt_readrxdata(rx_buffer, frame_len, 0);//¶ÁÈ¡½ÓÊÕÊý¾Ý


				/* Check that the frame is a final message sent by "DS TWR initiator" example.
				 * As the sequence number field of the frame is not used in this example, it can be zeroed to ease the validation of the frame. */
				rx_buffer[ALL_MSG_SN_IDX] = 0;
				if (rx_buffer[MESSAGE_TYPE_IDX] == FINAL&&rx_buffer[TAG_ID_IDX]==tag_id_recv&&rx_buffer[ANCHOR_ID_IDX]==g_com_map[DEV_ID]) //ÅжÏÊÇ·ñΪFinal°ü
				{
					uint32_t poll_tx_ts, resp_rx_ts, final_tx_ts;
					uint32_t poll_rx_ts_32, resp_tx_ts_32, final_rx_ts_32;
					double Ra, Rb, Da, Db;
					int64_t tof_dtu;

					/* Retrieve response transmission and final reception timestamps. */
					resp_tx_ts = get_tx_timestamp_u64();//»ñµÃresponse·¢ËÍʱ¼äT3
					final_rx_ts = get_rx_timestamp_u64();//»ñµÃfinal½ÓÊÕʱ¼äT6

					/* Get timestamps embedded in the final message. */
					final_msg_get_ts(&rx_buffer[FINAL_MSG_POLL_TX_TS_IDX], &poll_tx_ts);//´Ó½ÓÊÕÊý¾ÝÖжÁÈ¡T1£¬T4£¬T5
					final_msg_get_ts(&rx_buffer[FINAL_MSG_RESP_RX_TS_IDX], &resp_rx_ts);
					final_msg_get_ts(&rx_buffer[FINAL_MSG_FINAL_TX_TS_IDX], &final_tx_ts);

					/* Compute time of flight. 32-bit subtractions give correct answers even if clock has wrapped. See NOTE 10 below. */
					poll_rx_ts_32 = (uint32_t)poll_rx_ts;//ʹÓÃ32λÊý¾Ý¼ÆËã
					resp_tx_ts_32 = (uint32_t)resp_tx_ts;
					final_rx_ts_32 = (uint32_t)final_rx_ts;
					Ra = (double)(resp_rx_ts - poll_tx_ts);//Tround1 = T4 - T1
					Rb = (double)(final_rx_ts_32 - resp_tx_ts_32);//Tround2 = T6 - T3
					Da = (double)(final_tx_ts - resp_rx_ts);//Treply2 = T5 - T4
					Db = (double)(resp_tx_ts_32 - poll_rx_ts_32);//Treply1 = T3 - T2
					tof_dtu = (int64_t)((Ra * Rb - Da * Db) / (Ra + Rb + Da + Db));//¼ÆË㹫ʽ

					tof = tof_dtu * DWT_TIME_UNITS;
					distance = tof * SPEED_OF_LIGHT;//¾àÀë=¹âËÙ*·ÉÐÐʱ¼ä
					dist_no_bias = distance - dwt_getrangebias(config.chan, (float)distance, config.prf); //¾àÀë¼õÈ¥½ÃÕýϵÊý

					dist_cm = dist_no_bias * 100; //dis Ϊµ¥Î»ÎªcmµÄ¾àÀë
//					dist[TAG_ID] = LP(dis, TAG_ID); //LP ΪµÍͨÂ˲¨Æ÷£¬ÈÃÊý¾Ý¸üÎȶ¨
					
					/*--------------------------ÒÔÏÂΪ·Ç²â¾àÂß¼­------------------------*/
					LED0_BLINK; //ÿ³É¹¦Ò»´ÎͨѶÔòÉÁ˸һ´Î
					g_UWB_com_interval = 0;
					dis_after_filter=dist_cm;
					g_Tagdist[tag_id_recv]=dist_cm;
					if(g_pairstart==1&&dist_cm<20)
					{
						g_pairstart=0;
						g_com_map[PAIR_ID]=tag_id_recv;
						save_com_map_to_flash();
						BEEP2_ON;
						delay_ms(1000);
						printf("Pair Finish PairID: %d. \r\n",g_com_map[PAIR_ID]);
					}
					g_flag_Taggetdist[tag_id_recv]=0;
					printf("Anchor ID: %d, Tag ID: %d, Dist = %d cm\n", g_com_map[DEV_ID], tag_id_recv, (uint16_t)dis_after_filter);
					//dis_after_filter = LP_Frac_Update(p_Dis_Filter, dist_cm);

				}
			}
			else
			{
				/* Clear RX error events in the DW1000 status register. */
				dwt_write32bitreg(SYS_STATUS_ID, SYS_STATUS_ALL_RX_ERR);
			}
		}
	}
	else
	{
		/* Clear RX error events in the DW1000 status register. */
		dwt_write32bitreg(SYS_STATUS_ID, SYS_STATUS_ALL_RX_ERR);
	}
}

/*****************************************************************************************************************************************************
 * NOTES:
 *
 * 1. The sum of the values is the TX to RX antenna delay, experimentally determined by a calibration process. Here we use a hard coded typical value
 *    but, in a real application, each device should have its own antenna delay properly calibrated to get the best possible precision when performing
 *    range measurements.
 * 2. The messages here are similar to those used in the DecaRanging ARM application (shipped with EVK1000 kit). They comply with the IEEE
 *    802.15.4 standard MAC data frame encoding and they are following the ISO/IEC:24730-62:2013 standard. The messages used are:
 *     - a poll message sent by the initiator to trigger the ranging exchange.
 *     - a response message sent by the responder allowing the initiator to go on with the process
 *     - a final message sent by the initiator to complete the exchange and provide all information needed by the responder to compute the
 *       time-of-flight (distance) estimate.
 *    The first 10 bytes of those frame are common and are composed of the following fields:
 *     - byte 0/1: frame control (0x8841 to indicate a data frame using 16-bit addressing).
 *     - byte 2: sequence number, incremented for each new frame.
 *     - byte 3/4: PAN TAG_ID (0xDECA).
 *     - byte 5/6: destination address, see NOTE 3 below.
 *     - byte 7/8: source address, see NOTE 3 below.
 *     - byte 9: function code (specific values to indicate which message it is in the ranging process).
 *    The remaining bytes are specific to each message as follows:
 *    Poll message:
 *     - no more data
 *    Response message:
 *     - byte 10: activity code (0x02 to tell the initiator to go on with the ranging exchange).
 *     - byte 11/12: activity parameter, not used here for activity code 0x02.
 *    Final message:
 *     - byte 10 -> 13: poll message transmission timestamp.
 *     - byte 14 -> 17: response message reception timestamp.
 *     - byte 18 -> 21: final message transmission timestamp.
 *    All messages end with a 2-byte checksum automatically set by DW1000.
 * 3. Source and destination addresses are hard coded constants in this example to keep it simple but for a real product every device should have a
 *    unique TAG_ID. Here, 16-bit addressing is used to keep the messages as short as possible but, in an actual application, this should be done only
 *    after an exchange of specific messages used to define those short addresses for each device participating to the ranging exchange.
 * 4. Delays between frames have been chosen here to ensure proper synchronisation of transmission and reception of the frames between the initiator
 *    and the responder and to ensure a correct accuracy of the computed distance. The user is referred to DecaRanging ARM Source Code Guide for more
 *    details about the timings involved in the ranging process.
 * 5. This timeout is for complete reception of a frame, i.e. timeout duration must take into account the length of the expected frame. Here the value
 *    is arbitrary but chosen large enough to make sure that there is enough time to receive the complete response frame sent by the responder at the
 *    110k data rate used (around 3 ms).
 * 6. In a real application, for optimum performance within regulatory limits, it may be necessary to set TX pulse bandwidth and TX power, (using
 *    the dwt_configuretxrf API call) to per device calibrated values saved in the target system or the DW1000 OTP memory.
 * 7. dwt_writetxdata() takes the full size of the message as a parameter but only copies (size - 2) bytes as the check-sum at the end of the frame is
 *    automatically appended by the DW1000. This means that our variable could be two bytes shorter without losing any data (but the sizeof would not
 *    work anymore then as we would still have to indicate the full length of the frame to dwt_writetxdata()). It is also to be noted that, when using
 *    delayed send, the time set for transmission must be far enough in the future so that the DW1000 IC has the time to process and start the
 *    transmission of the frame at the wanted time. If the transmission command is issued too late compared to when the frame is supposed to be sent,
 *    this is indicated by an error code returned by dwt_starttx() API call. Here it is not tested, as the values of the delays between frames have
 *    been carefully defined to avoid this situation.
 * 8. We use polled mode of operation here to keep the example as simple as possible but all status events can be used to generate interrupts. Please
 *    refer to DW1000 User Manual for more details on "interrupts". It is also to be noted that STATUS register is 5 bytes long but, as the event we
 *    use are all in the first bytes of the register, we can use the simple dwt_read32bitreg() API call to access it instead of reading the whole 5
 *    bytes.
 * 9. As we want to send final TX timestamp in the final message, we have to compute it in advance instead of relying on the reading of DW1000
 *    register. Timestamps and delayed transmission time are both expressed in device time units so we just have to add the desired response delay to
 *    response RX timestamp to get final transmission time. The delayed transmission time resolution is 512 device time units which means that the
 *    lower 9 bits of the obtained value must be zeroed. This also allows to encode the 40-bit value in a 32-bit words by shifting the all-zero lower
 *    8 bits.
 * 10. In this operation, the high order byte of each 40-bit timestamps is discarded. This is acceptable as those time-stamps are not separated by
 *     more than 2**32 device time units (which is around 67 ms) which means that the calculation of the round-trip delays (needed in the
 *     time-of-flight computation) can be handled by a 32-bit subtraction.
 * 11. The user is referred to DecaRanging ARM application (distributed with EVK1000 product) for additional practical example of usage, and to the
 *     DW1000 API Guide for more details on the DW1000 driver functions.
 ****************************************************************************************************************************************************/